NSSearchPathForDirectoriesInDomains 三个参数详解

NSSearchPathForDirectoriesInDomains

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#import "NSString+FilePath.h"

@implementation NSString (FilePath)

//检索指定路径

//第一个参数指定了搜索的路径名称,NSDocumentDirectory表示是在Documents中寻找.NSCacheDirectory的话就是在cache文件中寻找.第二个参数限定了文件的检索范围只在沙箱内部.其意义为用户电脑主目录.也可以修改为网络主机等.最后一个参数决定了是否展开波浪线符号.展开后才是完整路径,这个布尔值一直为YES.

//该方法返回值为一个数组,在iphone中由于只有一个唯一路径(相对OC而言),所以直接取数组第一个元素即可.

+ (NSString *)documentsPath

{

    return [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES)
objectAtIndex:0];

}

//在上一步获得的路径后面加上文件的名字(用字符串的拼接方法).这样使用的返回路径就可以找到指定文件,文件的读取和写入便能够顺利完成了.

+ (NSString *)filePathAtDocumentWithFileName:(NSString *)fileName

{

   
NSString *filePath = [[self
documentsPath]stringByAppendingPathComponent:fileName];

   
return filePath;

}

@end

目录类型 

NSSearchPathDirectory

enum {

NSApplicationDirectory = 1,//Supported applications (/Applications)

NSDemoApplicationDirectory,//Unsupported applications and demonstration versions

NSDeveloperApplicationDirectory,//Developer applications (/Developer/Applications)

NSAdminApplicationDirectory,//System and network administration applications

NSLibraryDirectory,//Various user-visible documentation, support, and configuration files (/Library)

NSDeveloperDirectory,//Developer resources (/Developer)

NSUserDirectory,//User home directories (/Users)

NSDocumentationDirectory,//

NSDocumentDirectory,//

NSCoreServiceDirectory,//Location of core services (System/Library/CoreServices)

NSAutosavedInformationDirectory = 11,//Location of user’s autosaved documents Library/Autosave Information

NSDesktopDirectory = 12,//

NSCachesDirectory = 13,//Location of discardable cache files (Library/Caches)

NSApplicationSupportDirectory = 14,//Location of application support files (Library/Application Support)

NSDownloadsDirectory = 15,//

NSInputMethodsDirectory = 16,//

NSMoviesDirectory = 17,//

NSMusicDirectory = 18,//

NSPicturesDirectory = 19,//

NSPrinterDescriptionDirectory = 20,//

NSSharedPublicDirectory = 21,//

NSPreferencePanesDirectory = 22,//

NSItemReplacementDirectory = 99,//

NSAllApplicationsDirectory = 100,//

NSAllLibrariesDirectory = 101//

};

typedef NSUInteger NSSearchPathDirectory;

 

 

enum {

NSUserDomainMask = 1,//用户主目录中

NSLocalDomainMask = 2,//当前机器中

NSNetworkDomainMask = 4,//网络中可见的主机

NSSystemDomainMask = 8,//系统目录,不可修改(/System)

NSAllDomainsMask = 0x0ffff,//全部

};

typedef NSUInteger NSSearchPathDomainMask;

 

expandTilde = YES

展开成完整路径